| Message ID | 1398904476-26200-13-git-send-email-s-anna@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Rob, On 04/30/2014 07:34 PM, Suman Anna wrote: > The property 'hwlock-reserved-locks' will be used to represent > the number of locks to be reserved for clients that would need > to request/operate on specific locks. A new OF helper function, > of_hwspin_lock_get_num_reserved_locks(), is added to minimize > duplication in different platform implementations. > > The function will return a value of 0 if the property is not > defined, so as to support a default behavior of marking all > locks as unused and open for anonymous allocations. > > Signed-off-by: Suman Anna <s-anna@ti.com> > --- > .../devicetree/bindings/hwlock/hwlock.txt | 3 +++ > drivers/hwspinlock/hwspinlock_core.c | 25 ++++++++++++++++++++++ > include/linux/hwspinlock.h | 1 + > 3 files changed, 29 insertions(+) > > diff --git a/Documentation/devicetree/bindings/hwlock/hwlock.txt b/Documentation/devicetree/bindings/hwlock/hwlock.txt > index d538a9b..88d16d2 100644 > --- a/Documentation/devicetree/bindings/hwlock/hwlock.txt > +++ b/Documentation/devicetree/bindings/hwlock/hwlock.txt > @@ -18,6 +18,9 @@ Common properties: > property is needed on hwlock devices, where the number > of supported locks within a hwlock device cannot be > read from a register. > +- hwlock-reserved-locks: Number of locks to reserve for clients requiring > + specific locks. This value cannot exceed the value of > + hwlock-num-locks. Any suggestions here on the approach? This property falls into a gray area as well, as the current approach is somewhat limiting (it doesn't support sparse reserved locks, and expects them at the beginning of the lock range). regards Suman > - hwlock-base-id: An unique base Id for the locks for a particular hwlock > device. This property is mandatory ONLY if a SoC has > several hwlock devices. > diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c > index e05cea8..e74b55b 100644 > --- a/drivers/hwspinlock/hwspinlock_core.c > +++ b/drivers/hwspinlock/hwspinlock_core.c > @@ -286,6 +286,31 @@ int of_hwspin_lock_get_base_id(struct device_node *dn) > EXPORT_SYMBOL_GPL(of_hwspin_lock_get_base_id); > > /** > + * of_hwspin_lock_get_num_reserved_locks() - retrieve number of reserved locks > + * @dn: device node pointer > + * > + * This is an OF helper function that can be called by the underlying platform > + * specific implementations, to retrieve the number of locks to reserve from > + * the hwspinlock device instance's base id. The hwlock-reserved-locks DT > + * property needs to be defined for requesting any DT-based locks. > + * > + * Returns a positive number of locks on success, a default value of 0 if the > + * property is missing or an appropriate error code as returned by the OF layer > + */ > +int of_hwspin_lock_get_num_reserved_locks(struct device_node *dn) > +{ > + unsigned int val = 0; > + int ret; > + > + ret = of_property_read_u32(dn, "hwlock-reserved-locks", &val); > + if (!ret || ret == -EINVAL) > + ret = val; > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(of_hwspin_lock_get_num_reserved_locks); > + > +/** > * of_hwspin_lock_get_num_locks() - OF helper to retrieve number of locks > * @dn: device node pointer > * > diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h > index d120035..d18431f 100644 > --- a/include/linux/hwspinlock.h > +++ b/include/linux/hwspinlock.h > @@ -69,6 +69,7 @@ int of_hwspin_lock_simple_xlate(struct hwspinlock_device *bank, > const struct of_phandle_args *hwlock_spec); > int of_hwspin_lock_get_base_id(struct device_node *dn); > int of_hwspin_lock_get_num_locks(struct device_node *dn); > +int of_hwspin_lock_get_num_reserved_locks(struct device_node *dn); > int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, > const struct hwspinlock_ops *ops, int base_id, int num_locks, > int num_reserved_locks); > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, May 05, 2014 at 04:44:25PM -0500, Suman Anna wrote: > Hi Rob, > > On 04/30/2014 07:34 PM, Suman Anna wrote: > > The property 'hwlock-reserved-locks' will be used to represent > > the number of locks to be reserved for clients that would need > > to request/operate on specific locks. A new OF helper function, > > of_hwspin_lock_get_num_reserved_locks(), is added to minimize > > duplication in different platform implementations. > > > > The function will return a value of 0 if the property is not > > defined, so as to support a default behavior of marking all > > locks as unused and open for anonymous allocations. > > > > Signed-off-by: Suman Anna <s-anna@ti.com> > > --- > > .../devicetree/bindings/hwlock/hwlock.txt | 3 +++ > > drivers/hwspinlock/hwspinlock_core.c | 25 ++++++++++++++++++++++ > > include/linux/hwspinlock.h | 1 + > > 3 files changed, 29 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/hwlock/hwlock.txt b/Documentation/devicetree/bindings/hwlock/hwlock.txt > > index d538a9b..88d16d2 100644 > > --- a/Documentation/devicetree/bindings/hwlock/hwlock.txt > > +++ b/Documentation/devicetree/bindings/hwlock/hwlock.txt > > @@ -18,6 +18,9 @@ Common properties: > > property is needed on hwlock devices, where the number > > of supported locks within a hwlock device cannot be > > read from a register. > > +- hwlock-reserved-locks: Number of locks to reserve for clients requiring > > + specific locks. This value cannot exceed the value of > > + hwlock-num-locks. > > Any suggestions here on the approach? This property falls into a gray > area as well, as the current approach is somewhat limiting (it doesn't > support sparse reserved locks, and expects them at the beginning of the > lock range). Is it possible to implement a pinctrl-like hogging approach, whereby the specific locks that need to be reserved are consumed by the controller itself? Josh
diff --git a/Documentation/devicetree/bindings/hwlock/hwlock.txt b/Documentation/devicetree/bindings/hwlock/hwlock.txt index d538a9b..88d16d2 100644 --- a/Documentation/devicetree/bindings/hwlock/hwlock.txt +++ b/Documentation/devicetree/bindings/hwlock/hwlock.txt @@ -18,6 +18,9 @@ Common properties: property is needed on hwlock devices, where the number of supported locks within a hwlock device cannot be read from a register. +- hwlock-reserved-locks: Number of locks to reserve for clients requiring + specific locks. This value cannot exceed the value of + hwlock-num-locks. - hwlock-base-id: An unique base Id for the locks for a particular hwlock device. This property is mandatory ONLY if a SoC has several hwlock devices. diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index e05cea8..e74b55b 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -286,6 +286,31 @@ int of_hwspin_lock_get_base_id(struct device_node *dn) EXPORT_SYMBOL_GPL(of_hwspin_lock_get_base_id); /** + * of_hwspin_lock_get_num_reserved_locks() - retrieve number of reserved locks + * @dn: device node pointer + * + * This is an OF helper function that can be called by the underlying platform + * specific implementations, to retrieve the number of locks to reserve from + * the hwspinlock device instance's base id. The hwlock-reserved-locks DT + * property needs to be defined for requesting any DT-based locks. + * + * Returns a positive number of locks on success, a default value of 0 if the + * property is missing or an appropriate error code as returned by the OF layer + */ +int of_hwspin_lock_get_num_reserved_locks(struct device_node *dn) +{ + unsigned int val = 0; + int ret; + + ret = of_property_read_u32(dn, "hwlock-reserved-locks", &val); + if (!ret || ret == -EINVAL) + ret = val; + + return ret; +} +EXPORT_SYMBOL_GPL(of_hwspin_lock_get_num_reserved_locks); + +/** * of_hwspin_lock_get_num_locks() - OF helper to retrieve number of locks * @dn: device node pointer * diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h index d120035..d18431f 100644 --- a/include/linux/hwspinlock.h +++ b/include/linux/hwspinlock.h @@ -69,6 +69,7 @@ int of_hwspin_lock_simple_xlate(struct hwspinlock_device *bank, const struct of_phandle_args *hwlock_spec); int of_hwspin_lock_get_base_id(struct device_node *dn); int of_hwspin_lock_get_num_locks(struct device_node *dn); +int of_hwspin_lock_get_num_reserved_locks(struct device_node *dn); int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, const struct hwspinlock_ops *ops, int base_id, int num_locks, int num_reserved_locks);
The property 'hwlock-reserved-locks' will be used to represent the number of locks to be reserved for clients that would need to request/operate on specific locks. A new OF helper function, of_hwspin_lock_get_num_reserved_locks(), is added to minimize duplication in different platform implementations. The function will return a value of 0 if the property is not defined, so as to support a default behavior of marking all locks as unused and open for anonymous allocations. Signed-off-by: Suman Anna <s-anna@ti.com> --- .../devicetree/bindings/hwlock/hwlock.txt | 3 +++ drivers/hwspinlock/hwspinlock_core.c | 25 ++++++++++++++++++++++ include/linux/hwspinlock.h | 1 + 3 files changed, 29 insertions(+)